California’s vernal pools are ephemeral wetlands that constitute biologically
diverse and unique ecosystems. They provide habitats for a wide range of
highly
adapted organisms not or hardly found elsewhere, including twenty-seven species
of special concern listed by the U.S. Fish and Wildlife Service. They also
function as feeding grounds for migratory birds and other animals of wider
distribution. In hydrological terms, vernal pool basins have dampening effects
on surface flows and subsurface water level fluctuations. Human activities
have already eliminated the large majority of vernal pools in California,
and the remaining pools are therefore the subject of a dedicated Recovery
Plan by the U.S. Fish and Wildlife Service. One of the specific Recovery
Tasks
listed in the Recovery Plan, is to inventory each pool within each remaining
complex in terms of species diversity and abundance. We therefore propose
to conduct an exploratory survey of nematodes in two pools from the Santa
Rosa Plateau Ecological Reserve. Nematodes or roundworms are an extremely
diverse group of invertebrate animals. They include many microscopic species,
and often dominate soils and sediments in numbers and diversity. Their ecological
roles and interactions with other organisms are manifold, including for example
regulation of decomposers such as bacteria and fungi, but also predation
on
other small organisms, parasitism of a wide range of plants and animals,
and source of food to many kinds of other animals in soils and sediments.
Despite
this ecological importance, nematodes are poorly known because of their sheer
abundance often exceeds the means of routine research projects, and because
their variable morphological appearance often defies accurate identification.
The proposed study would not only constitute the first survey of nematodes
from vernal pools in the world, but would also apply a novel combination
of
microscopy and molecular analysis, to identify species and quantify their
abundance. The employed methods would result in the construction of a first
database of diagnostic DNA sequences, as well as a library of reference video
recordings at high magnification of the morphology of the discovered nematodes.
Both resources would provide an essential baseline for future surveys of
longer
duration an expanded geographical scope. Because of the wide range of ecological
requirements and behaviours exhibited by nematodes, the resulting data on
abundance and diversity of nematodes are expected to reveal correlations
with
important environmental parameters.They may therefore rove to be directly
relevant to bioassessment of ecosystem health of vernal pools, as well as
to the monitoring of the general effects of annual climate fluctuations,
and
the specific consequences of disturbances due to pollution or changes in
land use on the Santa Rosa Plateau. Given the current lack of knowledge on
nematodes
from this habitat, we also expect to discover new species. None of these
is likely to qualify for special status in terms of regulatory protection,
but
it is possible that some will be useful as bioindicator organisms for specific
changes or disturbances in vernal pools. In addition to output of scientific
data and possible monitoring tools, the project would also provide the setting
for the training of two undergraduate students in the many scientific skills
involved.